Derivative and Hedging Activities, Derivative Instruments Not Designated as Hedging Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Not Designated as Hedging Instrument | Trading assets | Interest rate-related instruments — customer and mirror
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	$ 2,626,982	$ 2,183,687
Derivative, Fair Value, Net	53,189	28,494
Not Designated as Hedging Instrument | Trading assets | Foreign currency exchange forwards
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	140,554	124,851
Derivative, Fair Value, Net	2,612	2,495
Not Designated as Hedging Instrument | Trading assets | Commodity contracts
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	467,979	457,868
Derivative, Fair Value, Net	47,089	38,686
Not Designated as Hedging Instrument | Trading liabilities | Interest rate-related instruments — customer and mirror
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	2,626,982	2,183,687
Derivative, Fair Value, Net	(52,238)	(28,035)
Not Designated as Hedging Instrument | Trading liabilities | Foreign currency exchange forwards
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	137,073	118,094
Derivative, Fair Value, Net	(2,484)	(2,339)
Not Designated as Hedging Instrument | Trading liabilities | Commodity contracts
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	467,957	457,108
Derivative, Fair Value, Net	(45,525)	(37,286)
Not Designated as Hedging Instrument | Other assets | Interest rate lock commitments (mortgage)
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	312,567	222,736
Derivative, Fair Value, Net	3,032	1,538
Not Designated as Hedging Instrument | Other assets | Purchased options (time deposit)
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	26,389	31,063
Derivative, Fair Value, Net	951	1,175
Not Designated as Hedging Instrument | Other liabilities | Forward commitments (mortgage)
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	245,000	164,567
Derivative, Fair Value, Net	(303)	(313)
Not Designated as Hedging Instrument | Other liabilities | Written options (time deposit)
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	26,389	31,063
Derivative, Fair Value, Net	(951)	(1,175)
Designated as Hedging Instrument | Other assets | interest rate product [Member]
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	250,000	0
Derivative, Fair Value, Net	$ 258	$ 0